arbenelux.com Open in urlscan Pro
136.144.201.5  Public Scan

Form analysis
0 forms found in the DOM

Text Content

 * Home
 * Suppliers
   * EMC
   * RF & Microwave
   * Satcom
   * AC/DC Power
   * Oscilloscopes
   * Electrical Safety
   * Test & Measurement
 * Applications
   * EMC
   * RF/Microwave
   * Satcom
   * AC/DC Power
   * Electrical Safety
   * Oscilloscopes
   * Test & Measurement
 * Service
   * Repair and Maintenance
   * RMA Request
   * Custom Projects
 * AR Benelux
   * Webinars
   * Agenda
   * Company information
   * Sales Conditions
   * Privacy Policy
 * Demo Sale
 * News
   * Subscribe to Newsletter
 * Contact Us
   * Contact


AR Benelux > Algemeen > Pre-Compliance EMC Testing with a Real Time Scope


PRE-COMPLIANCE EMC TESTING WITH A REAL TIME SCOPE

In the past two months, Teledyne LeCroy has launched several technical resources
on EMC / EMI measurements with real-time oscilloscopes.

 

FREE ON-DEMAND WEBINARS BY SIGNAL INTEGRITY EVANGELIST DR. ERIC BOGATIN

Recently, Teledyne LeCroy has published a two-part webinar series about how
real-time oscilloscopes and near field probes can be used in pre-compliance EMC
Testing. In these webinars Dr. Eric Bogatin, known for years as signal
evangelist, demonstrates how to transform time domain information into real time
spectrum in the frequency domain.

 * Part 1: Pre-Compliance EMC Testing with a Real Time Scope
 * Part 2: Pre-Compliance EMC Testing with Real-time Spectral Analysis

 

TEST HAPPENS BLOG

For more information on EMC testing with oscilloscopes, we also recomment
reading recently added articles in Teledyne LeCroys Test Happens BLOG.

TESTING FOR NEAR FIELD RADIATED EMISSIONS IN THE TIME DOMAIN

There are three, principal root causes of the common currents that lead to
radiated emissions in electronic devices:

 1. Return path discontinuities
 2. Physical structures that are not tightly coupled to the return plane
 3. Ground loops causing common currents in cables

We’ll briefly demonstrate a bench top test for finding sources of near field
radiated emissions caused by return path discontinuities using a real-time
oscilloscope in the time domain.

Why the time domain? Although EMC compliance testing is done in the frequency
domain, in the time domain we can see the signatures of near field emissions in
a way that yields information about the root causes of those emissions. It is a
type of pre-compliance EMC testing that can be easily done in your lab, without
the expense of an anechoic chamber.

NEAR FIELD VS. FAR FIELD RADIATED EMISSIONS

When we are testing a product on our bench top for EMC, we are in close vicinity
to that product in a typically noisy environment. All we can measure is the near
field, the electric or magnetic field strength in close proximity to our
product. It’s important to keep in mind that near field measurements are not the
same as the far field (3 m or more) measurements in the FCC Part 15 Radiated
Emissions test described earlier, and here’s why.

UNINTENTIONAL ANTENNAS IN ELECTRIC CIRCUITS

In our last post, we discussed how little radiated emissions it takes for an
electronic product to fail an FCC certification test for EMC.
Where do these radiated emissions come from? No one designing an electric
circuit board is designing them into their product on purpose. These sneaky
antennas do not appear in the schematic. However, we can unwittingly introduce
them into our product through certain styles of board and interconnect design
features. It is sometimes jokingly said there are two kinds of designers: those
who are designing antennas on purpose, and those who aren’t doing it on purpose.
We’re going to introduce two, basic models of antenna—magnetic dipole and
electric dipole (Figure 1)—to reveal a secret source of radiated emissions.

PRE-COMPLIANCE EMC TESTING USING A REAL-TIME OSCILLOSCOPE

When designing an electric circuit board, we always start with a schematic. All
it tells us is the components in use, how they are connected, and what the
functionality of the system is. The schematic tells us absolutely nothing about
signal integrity, power integrity or electromagnetic interference (EMI). All the
schematic tells us about is the connectivity.
Problems with signal integrity, power integrity and EMI all come to life when we
turn that schematic into a physical implementation, because once we have
connectivity established by the interconnects, the only thing interconnects are
going to do is screw up our beautiful design. They’re going introduce noise, and
that noise is going to cause some combination of signal integrity, power
integrity and EMI problems. The best we can do is to minimize its appearance and
impact using best design practices.

In this series, we’ll focus on design issues that affect EMI, and how you can
use a real-time oscilloscope to find the root causes of EMI that negatively
affect a product’s electromagnetic compatibility (EMC).





Contact AR Benelux



AR Benelux B.V.
Frankrijklaan 7
2391 PX Hazerswoude Dorp
The Netherlands
T: +31 172 423 000
F: +31 172 423 009
E: arbeneluxinfo@arworld.us
W: www.arbenelux.com

Sitemap | Email form

Other AR Websites
AR Europe
AR Deutschland GmbH
AR UK
AR France
AR RF/Microwave Instrumentation
AR Modular RF

© AR Benelux

 



previousnextslideshow